This invention relates to an electrical distribution system of the kind comprising a hollow conduit enclosing a plurality of continuous electrical conductors, access to the conductors being achieved by means of a contact plug which can be fitted into the housing at a series of entry points.
An electrical distribution system of this kind is described and claimed in U.S. Pat. No. 4,243,284, which describes a length of hollow conduit formed with an aperture in one wall through which a plug can be inserted; rotation of the plug brings its contact pins into contact with the conductors. A safety arrangement is provided, comprising a series of internal safety doors disposed within the conduit, which are biassed into normally closed positions in which they close off the part of the conduit containing the conductors from the aperture. The action of pushing a contact plug into the aperture opens the safety doors and enables the plug to be rotated into a position in which the contact pins contact the conductors. The design of the system makes access to the conductors by means other than the correct plug very difficult.
In U.S. patent application Ser. No. 314,819 a modified arrangement of this system is described in which a series of spaced apertures are used in combination with various alternative arrangements of safety doors.
A disadvantage of systems of this kind is that the mechanisms for the internal safety doors can be relatively complicated, and as a result difficulties can arise during assembly of the system, and particularly if servicing is required after installation. It is an object of the invention to provide an electrical distribution system of the kind described in which the safety door mechanisms are simplified such that assembly and servicing is greatly facilitated.